This application relates to a wheel mounting member for a vehicle wheel balancer. The invention cooperates with a standard threaded wingnut or xe2x80x9cquicknutxe2x80x9d to torque the vehicle wheel to the balancer. In order to obtain accurate balancing results, the wheel must remain precisely centered during operation of the wheel balancer. Upon rotation of the wheel, conventional electronic sensors and circuitry acquire data indicating the appropriate placement of balancing weights on the wheel. Proper wheel balancing is essential to achieving a smooth, vibration-free drive.
Conventional wheel mounting members include an annular flange plate with generally 3-8 removable wheel-engaging studs. The studs locate within the lug holes of the wheel, and can be arranged to match the particular lug hole pattern of the wheel being balanced. Upon tightening the wingnut on the balancer shaft, the studs cooperate to uniformly torque the wheel to the balancer. Such mounting members have been used in the wheel balancing industry for over 20 years, and are designed to serve two main purposes; first, to center the wheel on the balancer shaft to achieve optimal xe2x80x9cstaticxe2x80x9d balancing, and second, to torque the wheel to the balancer to achieve optimal xe2x80x9cdynamicxe2x80x9d balancing. While such mounting members are capable of both static and dynamic balancing, more accurate balancing results are generally achieved when using the mounting member in conjunction with a medium to high-angle standard centering cone. The centering cone fits within the center hole of the wheel opposite the mounting member, and is intended to pre-center or xe2x80x9cliftxe2x80x9d the wheel as the mounting member torques the wheel to balancer. Using a standard cone to pre-center the wheel, the mounting member is intended to achieve final wheel centering and torque.
In the past, most wheels were made of steel and did not have machined and accurate center holes. Traditional mounting members were designed to account for this inaccuracy. By using a medium to high angle cone at the center hole of the wheel, as the mounting member was urged against the wheel, it cooperated with the cone to lift and center the wheel on the balancer shaft. Cones with higher angles were used on wheels with less accurate center holes so that the mounting member served to do as much of the final static centering as possible.
To achieve precise accuracy, the flange plate of the mounting member has traditionally been produced of expensive drop forged tool steel which is hardened and ground. Each of the removable studs is likewise hardened and ground. The openings in the flange plate which receive the studs are traditionally honed to achieve an exact fit. Any compromise in this design would make the mounting member less accurate and shorten its useful life. While this mounting member works extremely well for centering and torque, because of its high tolerances and precise design, it is considerably expensive to produce and replace.
Since virtually all modern wheels have machined and accurate center holes, a very low angle or even cylindrical cone generally fits the wheels best and produces the best static balancing results without help from the mounting member. In other words, the wheel mounting member is no longer needed to achieve final static centering in wheels with highly accurate center holes. Its function in achieving proper dynamic balancing, however, is still essential. The invention, therefore, is an improved mounting member intended to torque, or dynamically balance, the vehicle wheel on the balancer without expensive design considerations necessary to achieve both static and dynamic balancing. The invention can be made of material other than steel, such as machined or injection molded plastic or other composite material.
Therefore, it is an object of the invention to provide an improved mounting member for a vehicle wheel balancer which serves to dynamically balance the vehicle wheel on the centering shaft of the balancer.
It is another object of the invention to provide a wheel mounting member which cooperates with a low angle centering sleeve to achieve precisely accurate static and dynamic balancing of the wheel on the centering shaft of the balancer.
It is another object of the invention to provide a wheel mounting member which cooperates with a wingnut to sufficiently torque the vehicle wheel onto the centering shaft such that the low angle sleeve achieves precise static centering.
It is another object of the invention to provide a wheel mounting member which has slight inherent flexibility.
It is another object of the invention to provide a wheel mounting member which will not scratch or otherwise damage the vehicle wheel.
It is another object of the invention to provide a wheel mounting member which is relatively lightweight and inexpensive to manufacture.
It is another object of the invention to provide a wheel mounting member which does not rely on high tolerances to produce accurate balancing results.
It is another object of the invention to provide a wheel mounting member which will not damage or create wear on the balancer shaft.
It is another object of the invention to provide a wheel mounting member which reduces the time and energy required to mount the vehicle wheel on the balancer.
It is another object of the invention to provide a wheel mounting member which is relatively easy to handle.
It is another object of the invention to provide a wheel mounting member which is durable.
It is another object of the invention to provide a wheel mounting member which includes a plastic centering stud having sufficient natural flex to ensure that virtually all static centering is achieved by a separate centering sleeve or low angle cone.
It is another object of the invention to provide a wheel mounting member which includes a plastic flange plate reinforced with an inexpensive metal in order to prevent flexing. Flexing in the plate would reduce the adaptors ability to apply the same amount of torque to each centering stud.
These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a wheel mounting member adapted for use in a vehicle wheel balancer to secure a vehicle wheel in a centered position relative to a centering shaft of the wheel balancer during wheel-balancing rotation of the wheel. The mounting member includes a base constructed of a polymeric material, and defining a center hole for receiving the centering shaft of the wheel balancer. A plurality of elongated wheel-engaging centering studs depend from the base and are adapted for engaging the vehicle wheel to mount the wheel on the balancer.
According to another preferred embodiment of the invention, the base has an annular flange.
According to another preferred embodiment of the invention, the centering stud is compressible along its longitudinal axis.
According to another preferred embodiment of the invention, the centering stud has an elongated stud shaft, and a head formed at a free end of the stud shaft and adapted for engaging the vehicle wheel.
According to another preferred embodiment of the invention, the head of the centering stud includes a reduced-diameter locating tip for locating the stud in a lug hole of the vehicle wheel.
According to another preferred embodiment of the invention, the base includes a reinforcing metal plate molded within the polymeric material.
According to another preferred embodiment of the invention, the centering stud includes a reinforcing metal rod molded within a polymeric material.
According to another preferred embodiment of the invention, the centering stud has a reinforcing metal tip including an anchor molded within a polymeric material.
In another embodiment, the invention is a vehicle wheel balancer for obtaining data relative to the imbalance of a vehicle wheel. The wheel balancer includes a centering shaft having a free end adapted for extending through a center hole of the wheel, and a proximal end opposite the free end. Means are provided for rotating the centering shaft. A locating hub is carried on the shaft and adapted for engaging a first side of the wheel to locate the wheel on the balancer. A centering sleeve is carried on the shaft adjacent the locating hub, and is adapted for extending through the center hole of the wheel from its first side to center the wheel relative to the shaft. A mounting member includes a base formed of a polymeric material, and defining a center hole for receiving the centering shaft of the wheel balancer. A plurality of elongated wheel-engaging centering studs depend from the base, and are adapted for engaging the vehicle wheel to mount the wheel on the balancer. The wheel is sandwiched between the centering studs and the locating hub such that the mounting member, locating hub, and centering sleeve cooperate to secure the wheel in a centered position relative to the shaft during wheel-balancing rotation of the wheel.